She's kept it a secret for over six months, but the name of Isla Fisher and Sacha Baron Cohen's second daughter has finally been revealed.

Sources say that the infant's name is Elula, the feminine form of the Hebrew word "Elul". This is the name of the the twelfth month of the Jewish civil year and the sixth month of the ecclesiastical year on the Hebrew calendar, which usually falls between August and September, about the time the baby was born.

True to form, Fisher and Baron Cohen did not reveal the birth date nor any pictures of their second daughter. Unlike most celebrities who can't wait to Tweet their baby news, the couple even refused to confirm Isla was pregnant again, despite her being pictured with a huge baby bump.

The pair were married in March last year after Fisher converted to Judaism. Their first daughter, Olive, was born in 2007.

Fisher is currently on the press circuit for her role voicing the character of Lucy in upcoming animated movie Rango.

Find out what mums are saying about the name in Essential Baby's Baby Names forum.